Despite advancements in materials and techniques for constructing and fabricating structures, it has been found that unwanted moisture may nevertheless intrude into a structure.
A structure such as a residential or commercial building may be considered to have an exterior building envelope that includes the exterior cladding of the walls and the roof. The exterior wall cladding may be brick masonry veneer, synthetic or masonry stucco, fiberboard siding, or other materials, while the roof may include asphalt shingles, tiles, built-up plies, sheet metal panels, or other systems. Typically beneath the envelope material is a vapor barrier, such as felt paper, tar paper, plastic sheeting, or other material. Beneath the vapor barrier is typically sheathing. Such sheathing typically is attached to the structural frame, such as wood studs. These components, together, constitute the structure itself. Few of these components are visible once the structure is completed, as only the exterior cladding is presented to view. The exterior envelope is intended in part to protect the components defining the structure from the intrusion of moisture. However, moisture may nevertheless intrude beyond the envelope into the structure.
Structural moisture intrusion into the building envelope can be quite damaging. Even small moisture quantities that have intruded beyond the exterior cladding or roofing of a structure promote the development and progression of wood-destroying organisms, rust, or other destructive and detrimental processes. The troubles caused by moisture intrusion are often exacerbated because the moisture intrudes only to unseen, interior portions of the structure, such as the interior portions of exterior walls in a building, and it is there, undetected, that the destructive and detrimental processes develop and grow. The structural damage resulting from such processes often cannot be detected until such damage has progressed so far, for so long, that its destruction progresses beyond the unseen, interior portions of the structure into adjacent visible portions of the structure. Such destructive progression exacerbates both the degree of damage and the costs of repairs to the structure.
As an example of such harmful effects, it has been discovered that moisture intrusion into a building often occurs at penetrations to the exterior cladding of the building, such as windows, doors, exterior lighting fixtures, exterior electrical outlets, side ventilations from dryers, and the like. It has also been found that such moisture intrusion occurs at junctures between the plane of a building roof and the plane of a building wall, especially when, for architectural reasons, the lower edge of the roof terminates within the plane of an exterior wall, or at the intersection of dormer window structures with building roofing systems, or, for example, at the juncture of a chimney structure with a building roofing system.
As a further illustrative example, moisture intrusion has been found to be a problem with buildings clad in synthetic stucco. From the nature of the material itself, synthetic stucco provides a moisture-proof exterior cladding, and building wall surfaces clad in the material are intended to be optimally moisture-proof. However, at stucco building wall surface penetrations, including windows, doors, exterior electrical outlet penetrations, and the like, the juncture of the terminating edge of the synthetic stucco exterior cladding with the adjoining edge of the penetrating component is susceptible to the intrusion of moisture. Once moisture penetrates into a synthetic stucco cladding system and seeps or migrates beyond such a juncture, it cannot escape or evaporate, because the synthetic stucco that clads the building at such locations is moisture-proof and thereby prevents or inhibits escape of the moisture. Accordingly, the moisture is trapped inside the exterior cladding of the building and is left to promote the development of organisms that cause the decay of building components such as sheathing, structural studs, window and door framing, and the like. The exemplified problem, however, is not confined to buildings utilizing exterior synthetic stucco cladding, and indeed has been found to occur in buildings using masonry products such as brick veneer, buildings using wood siding, and in other buildings using different materials and techniques for exterior cladding.
The problem of detecting and locating the intrusion of moisture beyond the exterior cladding of a structure is quite difficult to solve. Any system for solving the problem must be easily installed, as it will be installed in the field by craftsmen who are often under time constraints for completion of such construction and are not in possession of specialized tools dedicated to installation of particularized individual components. Furthermore, the spaces provided in such structures for disposition of system detection and location components at locations susceptible to such moisture intrusion are quite small—for example, moisture can intrude at the juncture of a exterior building cladding system and a window frame, which involves the space of only a small fraction of an inch. Moreover, given the variety of designs employed in architectural and other structures, almost an infinite variety of different configurations of framing members, sheathing components, window designs, door configurations, flashing details, joining techniques, and the like must be anticipated, and any system for detecting and locating the penetration of moisture should be easily adaptable in the field to such a variety of configurations. Any such system also must be able to detect quite small quantities of moisture, as it has been found that even small quantities are nevertheless sufficient for the promotion and development of destructive processes, particularly considering that such small quantities may be located within the structural system at a location that does not allow for escape or evaporation.
Any system for solving the problem of detecting and locating the intrusion of moisture beyond the exterior cladding of a structure, however, must provide early detection, before the development and progression of destructive processes such as rot or rust, thereby minimizing repair costs to the structure. Moreover, the damaging effects of moisture intrusion into a structure is cumulative, such that earlier detection will allow the avoidance of the compounding effect of multiple, future intrusions. If detected early, preventive measures, such as caulking, adjustment of flashing, repair of roofing shingles, and the like, may be undertaken that will remediate the problem. However, visual detection often cannot be provided, because moisture intrusion often stops within walls, window systems, door systems, and so forth, and it is there that the rot or rust begins; such a system must provide for detection and location notwithstanding the absence of visual indicia of such moisture intrusion.
Additionally, such a system for detecting and locating the intrusion of moisture beyond the exterior cladding of a structure must be very durable, and should be expected to have a service lifetime exceeding the lifetime of the structure in which it is installed. Of course, any system for the detection of moisture also must be reliable, a quality promoted by greater simplicity in the design of such a system and its components. At the same time, though, such a system must require little to no maintenance, as it is the sense of security promoted by installation of such a system that is the motivation on the part of the responsible party for such installation, and many of such system components may be built into such a structure during original construction and will not thereafter be accessible for later service.
Finally, a system for the detection and location of moisture in a structural system must provide for relatively inexpensive components, as it will be recognized that even a relatively simple structure contains a relatively large number of locations susceptible to moisture intrusion, such as multiple doors, windows, and so forth in a building system.
The present invention relates to an innovation and improvement over and upon the known systems for detecting and locating the intrusion and moisture beyond the exterior cladding of a structure at multiple locations, and provides distinct advantages over the known systems.